1. Field of the Invention
The present invention relates, in general, to an active safety apparatus for vehicles and, more particularly, to a technique of realizing optimal safety performance for a vehicle in the event of a vehicle collision by actively restraining passenger behavior in response to variations in passenger behavior in real time.
2. Description of Related Art
Airbag devices and seatbelt devices are representative examples of safety devices for vehicles. A conventional airbag device or a conventional seatbelt device has a drive mechanism as shown in FIG. 1. When a vehicle collision occurs, an airbag ECU or an FIS (Frontal Impact Sensor) outputs an airbag expanding signal so as to expand an airbag, and a seatbelt tension control device is operated to restrain the movement of a passenger.
However, the conventional safety device for vehicles is problematic in that once an operating signal is applied to the safety device in response to a vehicle collision, the safety device is expanded or operated by a predetermined physical quantity, such as a preset pressure or preset load, to protect a passenger, so that the safety device may fail to optimally protect the passenger given a specific vehicle collision condition or the vehicle collision velocity.
In other words, passenger behavior may greatly change depending on the vehicle collision conditions or the velocity of the vehicle collision. However, the conventional mechanism in which the passenger behavior is limited by a predetermined physical quantity may fail to optimally protect the passenger for a specific vehicle collision.
For reference, examples of cited documents disclosing a technique used to control the pressure at which an airbag expands or the strength with which a seatbelt is pulled in a vehicle collision are as follows.
Cited document 1: KR10-2004-0041350 A
Cited document 2: KR10-2001-0066080 A
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.